Offset in virtical soil stsack between floors?

[TwoBrowndogs]

Ok, so my questions is either “can I use an offset in soil stack between floors” or “anybody know how I can easily get closer to the soil stack without coming in from the rear”?

So, My house is a Victorian with only one toilet in the upstairs bathroom. To renovate the bathroom I took the opportunity to add a downstairs loo. It meant I could completely empty the bathroom and block up the original hole (the lead pipe exited at 45 deg off the centre and vertical). Meant I could later clean core cut a new hole. You can see in the photo the start of that PVC stack with downstairs branch. The stack is inserted into a stub of the old cast iron

I the issue I have is in creating the same branch upstairs actually positions the loo in the wrong place. I need to move the loo closer to the stack.

I see a couple of options:
1 – use a Y branch, that brings the outlet (closer than a 90 deg) to the stack by about 60 mm.

2 – use an offset (2 x 45 or 2 x 67.5) to move the stack further to the left and bring the loo into the back of the stack

3 .. any other option?

So from the highly skilled technical drawing:
A - ideal . .but can't
B - maybe but only moves entry across about 60mm compared to 90deg branch)
c - may work (but not sure of minimum offset with 2 x 45 deg)and not sure if I'm allowed to do this).

Am I allowed to put an offset into the vertical stack between floors with a loo above that offset?

Do I have any other choices (apart from running horizontally inside and coming into back of stack without offset)?

Many, many thanks for your thoughts.

 

[denso13]

Am I allowed to put an offset into the vertical stack between floors with a loo above that offset?

If the sizes work ok then yes, no problem.

 

[Hugh Jaleak]

Option B would be my first choice, but you can use the bends if you prefer. If you do, I'd personally fit them immediately underneath the junction where the WC outlet emerges. What you dont want is waste falling from height and hitting them, otherwise everyone knows what you've been doing....

Option D, (may possibly help), is to turn the junction so it goes into the wall at 45°, then fit another 45° bend in the wall to bring the soil pipe into the room square. Not sure if this would work for your situation?